--%>
Assignment Help - homework help

Problem on work of compression

A diesel engine operates devoid of a spark plug by using the high-temperature gas produced throughout the compression stage to ignite the fuel. During a typical compression, pure air that is originally at 21 °C and 0.95 bar is reversibly and adiabatically compressed to 1/20 of its original(actual) volume by the piston, as shown in the figure below.

a) If air is assumed to obey the ideal gas equation of state, find out the pressure and temperature in the cylinder at the end of the compression. The constant-pressure heat capacity of air varies with temperature and is given by

Cp/R = 3.3 + 6x10-4

b) What is the work of compression in J/mol of air?

c) Is the ideal gas law a good approximation in this case? Why?

2455_ideal gas law.jpg

   Related Questions in Mechanical Engineering

  • Q : Decrease in entropy with termperature

    Explain that Entropy decreases along with the increase in its temperature?

    		•
  • Q : Dynamic model for the paper machine

    Explain and derive the Dynamic model for the paper machine headbox?

    		•
  • Q : Hydrostatic System Explain the term

    Explain the term Hydrostatic System?

    		•
  • Q : Problem on discharge of water In the

    In the below system, d = 6 in., D = 12 in., Δz1 = 6 ft, and Δz2 = 12 ft. The discharge of water in the given system is 10 cfs. Is the machine a turbine or a pump ? Determine the pressures at points A and B? Neglect head losses. Suppos

    		•
  • Q : Problem on head loss The pump

    The pump illustrated in the figure adds 20 kW of power to the flowing water. The only vital loss is that which takes place across the filter at the inlet of the pump. Find out the head loss for this filter. Note that the gage pressure upstream of the filter is negativ

    		•
  • Q : Problem on turbulent flow The

    The approximate equation for the velocity distribution in a rectangular channel with the turbulent flow is 655_turbulent flow.jpg

    Q : Benefits of gear drive Benefits of gear

    Benefits of gear drive: In general, gear drive is helpful for power transmission among two shafts, which are close to each other (at most at 1m distance). Additionally, it has maximum efficiency while transmitting power. It is resilient as compare to

    		•
  • Q : Change of power in flow of kinetic

    Air at 20 m/s, 260 K, 75 kPa with 5 kg/s flows into a jet engine and it flows out at 500 m/s, 800 K, 75 kPa. What is the change (power) in flow of kinetic energy?

    		•
  • Q : Working environment in Product design

    Working environment: The conditions under which the product is likely to be used, stored, and transported must be specified. The product may have to operate in conditions of extreme temperature, be subject to vibration, radiation; these conditions wil

    		•
  • Q : Safe turbine operation For safe turbine

    For safe turbine operation how many governors are generally required and Why?

    		•